Development and validation of an ICF-based patient-reported outcome measure for patients with knee osteoarthritis: study protocol for a Delphi survey.

INTRODUCTION: Knee osteoarthritis (KOA) is a chronic disease that affects physical function, psychological well-being and has an impact on quality of life (QoL). Despite efforts to monitor QoL of patients with KOA, patient-reported outcome measures (PROMs) developed based on the comprehensive framework of the International Classification of Functioning, Disability and Health (ICF) remain limited. This protocol presents the phases of the development of a comprehensive KOA-specific PROM based on the ICF system METHODS AND ANALYSIS: This study follows the Patient-Reported Outcomes Measurement Information System (PROMIS) scientific standards for instrument development and validation. A qualitative phase, involving a systematic literature review and focus group interviews, will be conducted to establish the conceptual framework. A standardised item pool will be generated based on the ICF framework using refined ICF linking rules and thematic analysis. A modified Delphi process will be performed with a multidisciplinary expert panel to refine the items and establish the initial version, with consensus evaluation via a 4-point rating scale. Item reduction and psychometric evaluation will be informed by the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline. ETHICS AND DISSEMINATION: This study received ethical approval (K2024-082-01) from Tongren Hospital, Shanghai Jiao Tong University School of Medicine. Results from this cohort will be submitted to peer-reviewed scientific journals and reported at the leading national and international meetings in the field.